Mercedes did change the shift indicator light scheme in the later years, I read numerous posts here saying the shift indicator had its own bulb, I originally went down that path but that was not correct for my 83 126, the shift indicator lighting was fiber optic and its source is the same bulb as the upper console panel switch lights.Did you notice if the switch lights and shift indicator lights went out at the same time, if so they are most likely fiber optic, if not, then the shift indicator has is own bulb and the switch lights are fiber optic